Overbed table



April 7, 1970 F BURST ET AL 3,504,643

OVERBED TABLE Filed Sept. 26, 1966 5 Sheets-Sheet@ April 7, 1970 F, 1BURST EI'AL OVERBED TABLE Filed Sepf. 2e, 196e 3 Sheets-Sheet April 7,1970 F. J. BURST ET AL OVERBED TABLE 3 Sheets-Sheet 3 Filed Sept. 26,1966 (ya e? 5v fm nw? i n MM www a@ United States Patent O U.S. Cl.S-144 9 Claims ABSTRACT OF THE DISCLOSURE An overbed table rendered safefor use with electrically operated hi-low hospital beds by a lockmechanism that prevents downward movement of the table even though it beheavily overloaded, together `with manually operable mechanism forunlocking the table and moving the same downwardly.

BACKGROUND OF THE INVENTION This invention relates to overbed tables andhas for its principal object the provision of a new and improved tableof this type.

The present invention provides a crank-operated, springassisted overbedtable, which is equipped with a lock mechanism that denitely preventslowering the table, except through an operation of the crank, whilepermitting free upward movement of the table responsive to anapplication of a small force acting upwardly thereon.

Prior art overbed tables, of which we are aware, are of two generaltypes; namely, crank-operated and springassisted. In crank-operatedtables, once the table is moved to a particular position, it is lockedand cannot be moved either upwardly or downwardly until the crank isoperated. In prior art spring-assisted tables, downward movement of thetable is resisted by a brake mechanism which, in certain tables, permitsupward movement of the table without releasing the brake. In othertables of this type, a brake-releasing lever must be operated before thetable can be moved in either direction.

When used in connection with an electrically-operated hospital bed ofthe hi-low variety, discomfort and possible injury to the patient canresult when the spring frame of the bed is elevated while the table ispositioned thereover. A small upward movement of the spring frame of thebed brings the patient into contact with the overhanging portion of thetable, and if the table is locked, further upward movement of the springframe requires lifting the entire table. Since these tables are quiteheavy, lifting the entire table imposes a considerable weight upon thepatient. Certain spring-assisted overbed tables of the prior art providea lever disposed beneath the table which must be operated upwardly torelease the brake mechanism of the table. However, these releasinglevers are not extended the full length of the overhanging portion ofthe table and it is possible for a patient to engage the table withoutoperating this lever. In tables in which the brake mechanism permitsupward movement without specific release of the brake, this danger ofinjury to the patient is minimized.

Certain electrically-operated hi-low hospital beds are provided with alower frame which is not elevated when the spring frame is elevated, andas a result, the patient in such a bed may be squeezed after a slightupward movement of the table brings the floor-engaging portion thereofinto contact with the non-elevatable portion of the bed.

The present invention provides a table having a constant force spring,the strength of which is insufficient to elevate the table even when thetable is empty. A crank is provided and a cable employed to augment theforce of the spring when the crank is operated in one direction, therebyto elevate the table, and when the crank is operated in the ICC- reversedirection, the table is pulled downwardly against the force of thespring. The table of the present invention is provided with a lockmechanism which definitely prevents downward movement of the table, eventhough it be heavily overloaded, except through an operation of thecrank to unlock the locking mechanism and thereafter lower the table.The lock mechanism is arranged so that the table may be elevated whilelocked through the application of a small upward pressure thereupon.Through this arrangement, should the patient be elevated into contactwith the overhanging portion of the table by upward movement of thespring frame of the bed, only a slight force is necessary to elevate thetable and the discomfort of the patient is greatly reduced and thechances of injury to the patient are eliminated.

SUMMARY OF THE INVENTION This invention provides an overbed table thatcan be used over an electric hospital `bed with safety. The movableupper section of the table is urged upwardly by a constant force springmeans that is not quite strong enough to overcome the force of gravityacting on the section. The force of the spring means is transmitted tothe upper section by a presser tube which carries a sheave journalednear the spring means. A shaft journaled in the upper section carries alock mechanism which prevents counterclockwise rotation of the shaftwhile permitting free clockwise rotation thereof. A cable section woundclockwise around a drum xed upon the shaft extends therefrom around thesheave to a point of attachment to the lower section of the table. Asecond cable section extends from said point of attachment to said drumaround ywhich it is wound Counterclockwise, said first cable sectionpreventing downward movement of the top section when counterclockwiserotation of the shaft is prevented by said lock. Counterclockwiserotation of a crank on said shaft unlocks said lock mechanism and freesthe shaft to permit lowering the upper section by winding the secondsection of the cable upon said drum. The upper section is equipped witha pair of mirrors that are spring pressed into operative position as thetable top is moved laterally to expose the contents of a tray.

It is a main object of the invention to provide an overbed table that issafe under all conditions encountered during its use.

Another object of the invention is to provide an overbed table of ruggedconstruction that can be operated easily from one position to another bya patient.

Further objects of the invention, not specifically mentioned here, willbe apparent from the detailed description and claims which follow,reference being had to the accompanying drawings in which a preferredembodiment of the invention is shown by way of example and in which:

FIG. 1 is a perspective view of an overbed table embodying the teachingsof the invention;

FIG. 2 is an end elevational view, partly in section, and showing theupright post portion of the table;

FIG. 3 is a side elevational view, partly in section, and showingfurther details of the post structure;

FIG. 4 is a cross-sectional view taken substantially along the line 4 4of FIG. 2, looking in the direction of the arrows and drawn to anenlarged scale;

FIG. 5 is an edge view of a stationary lock plate;

FIG. 6 is a plan view of the lock plate;

FIG. 7 is an edge view of a lock housing;

FIG. 8 is a plan view of the lock housing;

FIG. 9 is an end view of the cable drum;

FIG. l0 is a plan view of the cable drum;

FIG. 11 is a fragmentary cross-sectional view taken along the line 11-11of FIG. 2, looking in the direction of the arrows and drawn to anenlarged scale;

FIG. 12 is a cross-sectional view taken along the line 12-12 of FIG. 11looking in the direction of the arrows and drawn to an enlarged scale;

FIG. 13 is a plan view of the overbed table frame;

FIG. 14 is an elevational view with the tray and top in place;

FIG. l5 is a plan view of the tray; and

FIG. 16 is a cross-sectional view taken along the line 16-16 of FIG 15looking in the direction of the arrows and drawn to an enlarged scale.

As will be seen in FIG. l, the overhead table consists of a base sectioncomprising end members and 11 between which an intermediate member 12 isextended to form a generally H-shape floor-engaging portion of thetable. Members 10, 11 and 12 are joined together in convenient mannersuch as by welding and preferably are composed of tubing. Casters 13 aremounted at the extremities of the members 10 and 11 to support the sameupon a floor.

Upstanding from the junction of base members 10 and 12 is a lower post15. As will be seen in FIGS. 1 and 4, post 15 is formed of two unequalU-shaped members telescoped together with the flanges of the smallermember attached to the end portions of the larger member. The web of thesmaller member forms the wall of an outwardly opening channel 16. Thesemembers are welded together and to the base members y10 and 12. Thelower section of the table is not elevated by an operation of the table.

Telescoped over the lower post 15 is an upper post 17 to the top ofwhich the table-supporting frame 18 and table top 19 are located. Fixedat the upper end of the post 17 is a housing 20, in which the crankmechanism of the table is positioned. The upper section of the tablethus formed is movable vertically with respect to the lower section.

As will be seen best in FIGS. l1 and l2, a base plate extends betweenopposite walls of the housing 20 and is fixed thereto preferably bywelding. Upstanding from plate 25 intermediate the ends thereof is abracket 26. Fitted in aligned perforations in the wall of housing 20 andin the bracket 26, are bushings 27 and 27A in which a shaft 28 isjournalled. Shaft 28 extends out of the housing through a perforation inthe opposite wall thereof.

Fixed on the wall of housing 20 through which the shaft extends is alock plate 30 that contains a circular perforation, the center of whichcoincides with the axis of the shaft. As will be seen best in FIGS. 5and 6, plate 30 contains a plurality of radially disposed teeth 31,separated by spaces of equal width.

Iournalled upon shaft 28 for rotational and axial movement is a lockhousing 32, best seen in FIGS. 7 and 8, which, on one of its faces, hasteeth 33 of size and position for fitting in the spaces between theteeth 31. Projecting from the other face of housing 32 is a ange 34which is interrupted to form diametrically opposed sockets 35.

As will be seen best in FIG. 12, a generally circular keeper 36 isfitted within the flange 34 and has radially extending ears 37 whichproject into sockets 35. Projecting inwardly of the keeper are camsurfaces which terminate in radially disposed shoulders 38 that lie onthe median lines of ears 37.

Disposed within keeper 36 is a cam lock 40 that is fitted on shaft 28and keyed against rotation thereon by engagement with opposed flat faceson the shaft. Projecting outwardly from the cam lock 40 are cams 41,shown to be three in number, each of which terminates in a radiallydisposed shoulder 42. It will be apparent that during clockwise rotationof the shaft cam lock 40 will reciprocate keeper 36 and thatcounterclockwise rotation will engage the radial shoulders on the camlock with the shoulders on the keeper.

The cavity in the lock housing 32 in which the cam lock 40 and thekeeper 36 are disposed is closed by a rectangular plate 43 which engagesopposite walls of the housing 20 and contains a perforation throughwhich shaft 28 projects. A spring 44 encircles shaft 28 and abutsagainst plate 43 and bushing 27A and is tensioned to urge the lockhousing to the left, as seen in FIG. ll, with the teeth 33 projectinginto the spaces between teeth 31 on the lock plate. The cavity in thelock housing is preferably filled with a suitable lubricant.

Mounted upon shaft 28 between bushings 27 and 27A is a cable drum 4Sbest seen in FIGS. 9, l0 and l1. This drum consists of a cylindricalportion 46 at one end of which is a collar 47 which contains a diagonalslot 48. The hub 49 contains a plurality of end opening U-shaped slots,six in number in the example shown. Also mounted upon the shaft is acollar 50 which is identical in construction with the collar portion 47of drum 45. A spacer 51 abuts against bushing 27 and the hub of collar50 to keep that collar abutted against the drum and the drum hub againstthe bushing 27A.

Mounted upon shaft 28 is a cylindrical sleeve 52 which projects throughthe openings in housing 20 and lock plate 30 into engagement with lockhousing 32. Sleeve 52 contains diametrically opposed diagonally disposedslots 54. A pin 53 disposed in a perforation in shaft 28 extends intoslots 54 to key sleeve onto the shaft while permitting limited rotaryand axial movement with respect to the shaft. Sleeve 52 is partiallydisposed within the hub of a crank 55 and is secured therein by a drivepin 56.

Normally spring 44 forces the lock housing 32 and the crank 55 outwardlyof the housing 20, positioning the pin 53 in the end of slot 54 in whichit is shown in FIG. 11. Clockwise rotation of the crank rotates theshaft and cam lock 40 moves the keeper 36 -back and forth laterally whenthe housing is in the position shown in FIG. 12. Counterclockwiserotation of crank 55 cams sleeve 52 inwardly of the housing 20 as pin 53moves from the end of slot 54, in which it is shown in FIG. 11, to theopposite end of the slot. Inward movement of sleeve 52 pushes lockhousing 32 inwardly compressing spring 44. This movement of housing 32disengages teeth 33 from teeth 31 on lock plate 30, freeing the housingfor rotation. Counterclockwise rotation of the shaft 28 drives cam lock40 which drives keeper 36 through engagement 0f a radial shoulder 42 onthe cam lock with one of the shoulders 38 on the keeper. Rotation of thekeeper 36 drives housing 32 through engagement of ears 37 with the edgesof slots 35. When the force rotating crank 55 counterclockwise isremoved, spring 44 restores the lock housing and crank to the positionshown in FIG. 1l.

Preferably bushings 27 and 27A, lock plate 30, lock housing 32, plate43, cable drum 45, collar 50 and sleeve 52, are composed of oilimpregnated sintered steel, commercially known as Oilite, although theuse of other materials therein is contemplated.

Fixed to the underside of base plate 25, by suitable means such asbolts, is a mounting plate 58 to which a rigid tube 59 is attached inconvenient manner such as by welding. Tube 59 extends downwardly andterminates in a pressure plate 60, FIGS. 2 and 3, which is attachedthereto in convenient manner such as by welding. Adjacent its lower end,tube 59 contains a slot 61 in which a sheave 62 is journalled.

As will be seen best in FIGS. 2, 3 and 4, a cable retainer 63 attachedto one sidewall of post 15, in convenient manner such as by screws,contains a formed portion 64 which is shaped to embrace a ball on acable to attach the cable to the post. Portion 65 of the retainerextends across the post and is fastened to the opposite wall thereof.Portion 65 extends downwardly and forms an up stop, as will presentlyappear. Section 66 of a cable extends downwardly from retainer 63,around sheave 62, thence upwardly alongside tube 59 to drum 45, thencethrough slot 48 into the collar 47. A ball on the end of the cableattaches it to the drum. The drum is then rotated clockwise to take upslack in the cable and then secured on the shaft by a drive pin 67 thatextends through slots in the hub 49 and a perforation in the shaft 28. Asection 68 of the cable extends upwardly from retainer 63, thencethrough the slot in collar 50 to which collar it is secured by a ball onthe end of the cable. Collar 50 is rotated counterclockwise to take upslack in the cable and is then secured on the shaft by a drive pin 69that extends through slots in the hub of the collar and a perforation inshaft 28.

Positioned in the lower 4post 15 is a U-shaped spring cage 70, theclosed end of which engages the presser plate 60. A pair of constantforce springs 71 are disposed between the side arms of the spring cageand wound around arbors 72 which are journalled in the cage by pins 73which project through perforations in the Side arms and into counterbores in the arbor. The heads of pins 73 engage the inner surface of theside walls of post 15 to guide the spring cage during movement withinthe post.

The ends 71A of the constant force springs 71 are unwound and extendedupwardly along the side Wall of the post 15 and are bolted to a hook 74that is hooked over the top edge of an end wall of the post to attachthe springs to the post. Constant force springs commercially availableunder the name NEGATOR have been found to be satisfactory for thispurpose. These springs when unwound tend to rewind themselves and,hence, with the arrangement shown, the spring cage 70 exerts a constantforce upwardly through the presser plate 60 and tube 59 to the movableportion of the table. This force is not suficient to overcome the pullof gravity on the upper portion of the table, but rather, falls short ofthe required force by a small amount, say about three pounds.

RAISING THE TABLE When it is desired to elevate the overbed portion ofthe table, crank 55 is operated in a clockwise direction. Pin 53 inengagement with the end 0f slot 54, as shown in FIG. 1l, keys the crankto the Shaft and drum 45 iS rotated. Rotation of drum 45 in a clockwisedirection winds the cable section 66 on the drum, thereby shortening thelength of the section of the Cable 66 between the retainer 63 and thesheave 62. This pull of the cable augments the force of springs 71,thereby raising the table upon the post 15. Clockwise rotation of thedrum 45 unwinds section 68 of the cable therefrom to lengthen the samebetween the point of attachment 63 and the drum.

During vertical movements of the post 17 with respect to the post 15,post 17 is guided by a pair of rollers 76 journalled at the top of thepost 15, which rollers engage the inner surfaces of opposed walls of thepost 17. A roller 77 journalled in a suitable bracket that is fixed atthe bottom of the post 17 is disposed in the channel 16 in the post 15engaging the web of the channel to aid in guiding the upper post. Aplurality of low friction plastic buttons 79, preferably nylon, carriedon the walls of one of the posts engage the adjacent walls of the otherpost to aid in guiding post 17. The spring cage 70 is guided by a roller78 that engages the web of channel 16 by the engagement of ends 71A ofsprings 71 with the end wall of post 15 and by the engagement of headsof pins 73 with the sidewalls of post 15.

Upward movement of the table can continue until the closed end of springcage 70 engages the bottom edge of up stop 65.

THE LOCK MECHANISM As will be seen best in FIG. l2, during rotation ofthe shaft clockwise, cams 41 on the Cam lock 40 engage the bosses on thekeeper 36 alternatively and impart a reciprocating motion to the keeperso long as the clockwise rotation of the shaft continues. When theoperating force on the crank is removed, the weight of the overbedportion of the table will cause slight counterclockwise rotation of theshaft, this rotation continuing until one of the shoulders 42 on the camlock engages a shoulder 38 on the keeper 36. This engagement preventsfurther counterclockwise rotation Of the shaft since the ears 37 engagedin the slots 35 prevent rotation of the keeper with respect to thehousing 32 and engagement of the teeth 33 with teeth 31 prevent rotationof the housing. Thus, there is provided a positive lock that preventsdownward movement of the overbed portion of the table, except through anoperation of the crank. Although the lock mechanism definitely preventslowering the table, it does not interfere with the raising of the same.Should a slight force acting upwardly on the table be sucient to augmentthe force of springs 71, the table will move upwardly. This upwardmovement of the table causes cable section 68 to rotate the shaft anddrum clockwise and cam lock 40 imparts reciprocating motion to thekeeper, the same as when the crank is operated clockwise.

LOWERING THE TABLE When it is desired to lower the table, crank 55 isoperated counterclockwise, the initial rotation moving the pin 53 fromthe position shown in FIG. 11 through the slot 54 to the opposite end ofthe slot. This movement cams the collar 52 and crank 55 inwardly therebymoving the lock housing 32 inwardly against the tension of spring 44.Inward movement of housing 32 disengages teeth 33 from teeth 31 freeingthe shaft 28 for counterclockwise rotation. This counterclockwiserotation winds the portion 68 of the cable onto the drum 45 and unwindsportion 66 of the cable therefrom. Through this o-peration, the table ispulled downwardly against the force of springs 71. As soon as thedesired position of the talble is reached and force removed from thecrank, spring 44 moves the housing 32 to re-engage teeth 33 with teeth31 and further downward movement of the table is thus prevented.

As will be seen best in FIGS. 3 and 13, the table frame 18 consists of ahollow rectangular frame 21, fixed to housing 20 in convenient mannersuch as by welding. Frame 21 is preferably formed of rectangular tubing.Reinforcing bars 22, preferably angles, are welded to the housing andframe. Fixed across the post end of frame 21 is a rail 23 that extendsacross the top of housing 20,

p FIGS. 3 and 13, from side to side of the frame. A second rail 24 isxed at the end of the frame remote the post.

Fitted in the table frame 18 is a tray 80, preferably composed of asuitable plastic, which tray has a planar upper portion 81 that restsupon frame 21 to support the tray on the frame. Portion 81 containsslots 82 through which rails 23 and 24 project when the tray ispositioned on the frame. The outer edge of the tray contains a dependingflange 83 disposed alongside the frame 21 to conceal the same. The trayis secured on the frame 21 by stops 84, FIG. 14, preferably com-posed ofplastic, through which are extended screws, not shown, that projectthrough perforatiions 85 in the tray and into tapped holes 86 in theframe. In addition to securing the tray on the frame, stops 84 limitlateral movement of the top 19, as will presently appear.

The portion of the tray within the frame 21 is depressed to form ashallow pocket 87 which merges into a deeper pocket 88 adjacent the postend of the frame. Rising out of the bottom of the tray are bosses 89 and89 located on the longitudinal median line of the tray. The bosses arepreferably rectangular in shape and terminate in at tops that aredisposed in a common horizontal plane.

Fixed to the tops of bosses 89 and 89 in convenient manner such as bybolts is the center section 90 of a hinge. One movable arm 91 ispivotally connected to section 90 by a pin 92, and to the frame 93 of amirror 94 in convenient manner such as by screws. A second movable arm95 is pivotally connected to section 90 by a pin 96 and to the frame 97of a mirror 98. A spring 99 surrounds each of the pins 92 and 96 and hasan end engaging the underside of the section 90 and an end engaging theedge of the associated mirror frame. The springs 99 are tensioned tomove the mirrors from a horizontal to an inclined position. Frames 93and 97 are composed of plastic and are devoid of sharp corners thatcould injure a patient.

Upstanding from the portion 81, at the ends of the tray, are bosses 100which are located upon the longitudinal median line of the tray. Eachboss 100 contains an indentation or dimple in its upper surface` Thetable top 19 may be composed of wood, chipboard or other suitablematerial surfaced with a stain-resistant material such as, for exam-ple,Formica. The top is held on the frame by 1brackets 101 of known designlocated on the longitudinal median line of the top. As shown best inFIG. 3, the brackets 101 are metal clips which carry metal spheres thatengage beneath the heads of rails 23 and 24 and provide for moving thetop laterally on the frame. This lateral movement is limited byengagement of the brackets 101 with the stops 84 to prevent unwantedremoval of the top from the frame.

Located on the underside of the top 19 and on the longitudinal medianline thereof are spring-pressed detents 102. which engage in the dimplesin bosses 100 when the top is centered on the frame. With the top socentered, springs 99 hold the mirror frames 93 and 96 in engagement withthe underside of the top, as shown in FIG. 16. As the top is movedlaterally from the full line to the dotted line position in this figure,when the trailing edge of the top moves out of engagement with themirror frame 93, spring 99 rotates the mirror clockwise around pin 92.By governing the position in which lateral movement of the top isstopped, the angle at which the mirror is placed can be fixed at theconvenience of the patient. Lateral movement of the top exposes articlesin the tray sections 87 and 88, rendering them readily accessible to thepatient.

As the top 19 is Imoved back to its normal position, the leading edge ofthe top engage the frame 93 and further movement cams the mirror backinto the position in which it is shown in FIG. 16. Movement of the topfrom center to the left, as seen in FIG. 16, permits the associatedspring to move mirror 98 upwardly in the same manner.

To insure that the overbed table will harmonize with the decor ofhospital rooms in which it will be used, the exposed metal parts arepainted with a neutral color such as light grey, for example. To enhancethe appearance of the table, the channel 16 in the post 15 is coveredwith a decorative channel shaped member 105, FlGS. 1 and 4, which fitsover the iianges of channel 16 and is secured to the web of that channelin convenient manner such as Iby screws. Member 105 extends upwardlyfrom base member 12 to a point above the lower edge of post 17 when theta'ble is elevated to its uppermost position.

To prevent chipping the paint on post 17, should the post be moved intocontact with a bed, a channel shaped member 106, FIGS. l and 4, is fixedupon the end of the post that is adjacent the channel 16 by a suitableadhesive. Member 106 extends from top to bottom of post 17. Preferablymembers 105 and 106 are composed of stainless steel, although the use ofother materials therein is contemplated.

The overbed table of the present invention combines the advantages ofspring assisted tables with the advantages of crank operated tables.Since the crank is only required to apply a small force augmenting theforce of the springs, gearing down of the crank is not necessary andonly a relatively few turns of the crank are all that are required tomove the table from its lowermost to its uppermost position. Thepositive action of the lock mechanism prevents unwanted downwardmovement even though the table be overloaded.

From the foregoing, it will be apparent that we have provided an overbedtable of rugged construction capable of performing in a satisfactorymanner with a minimum of maintenance. The table is completely safe touse under all conditions likely to be encountered, since the overhangingportion of the table is free to be moved upwardly by an application of asmall force thereon. At no time can the overhanging portion of the tablebe lowered, except through an operation of the crank. The table is ofpleasing appearance that fits well into the decor of the room in whichit is to be used.

Having thus complied with the statutes and shown and described apreferred embodiment of our invention, what we consider new and desireto have protected by Letters Patent is pointed out in the appendedclaims.

What we claim is:

1. An overbed table comprising:

( a) an upper section containing a post from the upper end of which atray supporting frame extends laterally and is covered by a table top, aoor supported lower section containing an upstanding post telescopedinto said upper section post said upper section being movable verticallywith respect to said lower section;

(b) a constant force spring means including a cage fixed with respect tothe upper section and movably disposed in the post of the lower section,a pair of constant force springs journaled in said cage, each having anend attached to the lower section, said springs tending to elevate theupper section;

(c) cable means operable to augment the force of said spring means toelevate the upper section and to lower that section against the force ofsaid spring means',

(d) and lock means in said upper section -for controlling said cablemeans to prevent only lowering the upper section.

2. An overbed table as specified in claim 1 in which the cage ispositioned by a rigid member that is fixed at the upper end of the uppersection post and is abutted against the cage and in which a sheave isjournaled in said member adjacent the abutting end thereof.

3. An overbed table as specified in claim 2 in which the cable meansincludes a drum fixed upon a shaft journaled at the top of the uppersection post; around said drum a first section of the cable is woundclockwise and extended therefrom around said sheave to a cable retainerfixed at the upper end of the lower section post, and a second sectionof said cable is extended from said retainer to said drum around whichit is Wound counterclockwise.

4. An overbed table as specified in claim 3 in which the cable retainerincludes an up stop portion adapted to engage the spring cage to limitupward movement of the upper section.

5. An overbed table as specified in claim 3 in which application offorce of said upper section suicient to augment said spring force movesthe section upwardly and rotates the shaft clockwise by unwinding thecable section that is wound counterclockwise on said drum.

6. An overbed table as specified in claim 3 in which the lock meansincludes a lock plate fixed against rotation and having teeth projecting`from one of its faces, a lock housing encircling the shaft and havingteeth registered with the lock plate teeth, a keeper within said housingfixed against rotation therein but capable of reciprocating movements, acam lock on said shaft fixed against rotation but capable of axialmovement thereon and having a plurality of shoulders, said keeper beingreciprocated by clockwise rotation of said shaft and cam lock and havingshoulders one of which is engaged by a shoulder on the cam lock byslight counterclockwise rotation to prevent further counterclockwiserotation of the shaft.

7. An overbed table as specified in claim 6 in which a crank has a hubin which a sleeve is lixed, said sleeve rotatably and slidably engagingsaid shaft and being keyed thereto by a pin that projects through theshaft into diagonally disposed slots in the sleeve, counterclockwiserotation of the crank moving the crank inwardly as said pin moves to oneend of said slots, said sleeve moving said lock housing teeth out ofregistration with said lock plate teeth to free the shaft forcounterelockwise rotation, a shaft encircling spring moving said lockhousing teeth back into registration with said lock plate teeth andmoving said crank outwardly when operating force is removed from thecrank.

8. An overbed table as specified in claim 1 in which a pair of mirrorsare supported on said tray by springpressed hinge means and maintainedin horizontal position through engagement with said top incontents-concealing position, each mirror being moved by said hingemeans out of horizontal into upstanding position as the top is movedlaterally out of engagement with that mirror.

9. An overbed table as specied in claim 8 in which the spring-pressedhinge means includes a central element Xed on the tray, a pair ofmovable members pivotally attached to said element, one on each sidethereof and attached to the frame of the associated mirror, and a pairof springs, one individual to each member.

References Cited UNITED STATES PATENTS 4/1944 Hillenbrand 108-50 X2/1953 Berner 10S-146 X 8/1954 Woller 10S-146 11/1954 Morrow 10S-1361/1956 Berner et al 108-50 X 6/1956 Smith 10S-147 9/ 1959 Sehlackman etal- 108--26 X 11/1964 Hinden et al 10S-150 X 12/ 1964 Armstrong 108-1477/1965 Linder et a1 108-146 6/ 1965 La Vigne 108-136 U.S. Cl. X.R.

